Record for sound-reproducing machines.



' R. M. HUNTER.

RECORD FOB sown) REPRODUGING MACHINES. APPLICATION FILED A'UG. 31,1907.

937,680. Patented 001;. 19, 1909.

' Tigl Jiig. 2.

- form a part thereof.

UNITED A STATES PATENT ornron.

RUDOLPH M. HUNTER, 0F PHILADELPHIA, PENNSYLVANIA.

nnconn non sormn nnrnonucme MACHINES.

To all whom it may concern:

Be it known that I, RUDOLPH M. HUNTER, of the city and county of Philadelphia and State of Pennsylvania, have invented an Improvement in Records for Sound-Reproducing Machines, of which the following is a specification.

My invention has reference to records for sound reproducing machines and consists of certain improvements which are fully set forth in the following specification and shown in the accompanying drawings which lihe object of my invention is to provide a construction of sound record tablet which, when operating in conjunction with the sound box and stylus, will, during the greater part of the time, cause a reproduction of the sounds without any feeding or propelling action upon the sound box and stylus or upon the record relatively to the sound box so that for about 95 per cent.v of

the time required to reproduce any piece, the

stylus simply responds to the reproducing of sound and is not influenced by lateral feeding across the record tablet.

The result of the above described method of reproducing sound is that less scratchy tones result and the reproduction is more accurate, because there are no continuous lateral strains caused by the transverse feeding or propelling of the stylus by the groove and hence the lateral vibrations of the stylus are equally free in both directions.

Myf vention more especially resides in the sound record tablet, and this comprises the operating surface whether in disk or cylindrical form in which the groove over the greater part of its length is so formed that there is no requirement for a transverse feeding of the stylus and sound box, sald feeding taking place only at widely sepa- .ago

rated intervals along the length of the groove vand then only for very short periods of time.

More specifically, my invention is applied- 1n its preferred form to what is known as the disk record such as employedin the'ordi nary gramophone, but the groove instead of being spiral is formed with a series of concentric circular parts connected byshort dinal grooved portions for feeding the stylus from the termination of one concentric groove to the beginning ofthe' next adjacent concentric groove, the construction being such that no feeding action upon the Specification of Letters Patent. Applicafion filed. August 31,1907. Serial No. 390 847.

, stitutes a very small travel of the concentric portions of the groove under the stylus and only during the time the short diagonal portions are operatin upon the stylus.

Ily invention also comprehends details of construction which, together with the features above specified, will be better understood by reference to the drawings, in

which:

Figure 1 is a plan view of a disk record embodying my invention; 2 is a crosssection of a portion of the same but on a larger'scale; Fig. 3 is an elevation of a portionof a cylindrical record tablet embodying Patented Oct. 19, 1909.

stylusacross the record tablet during the 'my invention; and Fig. 4 is a diagram illustrating the arrangement of the grooves when stretched out.

A isthe body of the record and is prolvided with a series of concentric circular record grooves I. These concentric grooves have a common center with the center of the disk and hence with the turn-table of the or-v dinary sound reproducing machine when the disk is applied thereto. The concentric grooves I are not complete circles but for a short space are open as to themselves, but the termination of the outer groove is connected with the beginning of the next adjacent groove by a short diagonal groove J and so on with each successive concentric groove, as clearly indicated. The beginning and termination of each of these concentric grooves I are separated between the radial dotted lines K and L, and the surface conortion of the surface of the entire record isk, and consequently thegrooved portions J likewise constitute a very small ortion of the total length of the grooves o the record disk. In Fig. 1,

the grooves I I are shown relatively far apart ,for clearness, and consequently the portionsJ have considerable obliquity, but

in actual practice, the concentric grooves I I are approximately 1/100 of an lllCll apart, and therefore the obliquity of the connecting grooved portions J is hardly perceptible and produces no undue effect upon the stylus with re d to the reproduction of sound because it passes under the stylus so quickly and at-such lo intervals that any diflen ence which mig t result-,would not be de tected by theear before it has occurred and passed. 'the operation of the major part of the length of the combined grooves on the stylus there is nodisturbing action afi'ectin the reproduction of sound due .to.

the fee ing action of the groove upon the stylus and sound box, which feeding action has heretofore required a greater pressure on one sideof the groove than on the other by the stylus, and which, to that extent, has

modified the purity of the tone which was reproduced by the instrument-i In Fig. 3, Ihave shown a portion of a 10, cylindrical record, and in this case, the

grooves I lie in planes at right angles to the secured where the record tablet is required to also feed the stylus, but because: of the I smaller diameter of the cylinder, there are relatively 'more of the diagonal grooved portions J, relatively to the length of the concentric portions 1, than is the case in the disk form in Fig. 2'.

If the grooves of Fig. 1 were stretched out,they would be as diagrammatically illus-f "trated in Fig. 4, from which it will be seen that the only'feeding action would be at the 4 short diagonal portions J, and then only for very short durations of thetotal time V it is required for the grooved portions to 1 passunder the st lus. From this it willbe seen that such de ects as are introduced intq the music orreproduction of sound, bythe ,fee 11 action of the groove upon the st lus is confined toa very small portion "ot the:

time which is required to reproduce the entire. com osition and then too, at widely separate intervals of time, so that the ear wouldnot be, alert enoughto detect an dif- 40 'ference before the cause for any such itfer-v ence in the reproductionof sound has passed.

4 Itw'ill,.of course, be understood that the general arrangement of the grooves illustrated in the drawings are more orless modified in their smoothness by the lateral sinuositieswhich are given to them'under the sound vibrations-through the recording stylus and which are totally; independent of the position of the grooves which are de- BOfined by the device employed to; relatively feed'the recording surface under the engravstylus when recording the sound record. do not limit myself'to the arrangement of all of the portions J in the same radial 155 position with respect to the surface of the recordtablet as it is evident that they may disposed inany other manner, regular or irregular asmay be desired, the 'eSs ential feature of the invention residing in the factfiothat the record tablet is so formed that a portion of the length of the groove therein .lsrequired .to per orm no function excepting that of reproducing sound,.whereas the remaining and preferably very limited portion of its length made to reproduce sound ters- Patent, is

I oeaeso and propel or feedthe stylus transversely across the record tablet.

'Having now described my invention, what I claim as newand desire to secure by. Let- '1. A flat sound record tablet having a V series of laterally undulating sound record grooves of even depth in concentric circular arrangement but each ,forming less than a full c rcle and having the terminations of each circular groove connected by sound record grooves respectively with the beginning of sound record grooves of next smaller circumference.

2. A flat sound record tablet having a series of laterally undulating sound record grooves in concentric circulararrangement but each forming less than a full circle and having the terminations of each circular groove connected by diagonally arranged sound record grooves respectively with the beginnin of sound record grooves of next smaller circumference.

c 3. A sound record tablet having its sur' 7 face provided with a series of sound record grooves of substantially uniform cross seoj tion and of successively shorter length connected in series by a series of short sections of sound record grooves arranged diagonally tothe' first mentlon'ed sound record grooves...

:4. A sound record tablet having its surface provided withaseries of concentrically arranged sound record. grooves of succes sively shorter length connected in series by a series of parallel short sections of sound record grooves arranged diagonally to the first mentionedsound record grooves.

5. A sound record tablet having a series of parallel laterally undulating sound record grooves-each of circular form and less than a fullcircleIand connecting sound record 'grooves diagonally arranged with respect to the'first mentioned grooves and connecting them in series.

. 6. A 'record' blet for soundproducing machines which consists of 'a surface having a laterally undulating sound record groove formed therein and in which the said groove is made up of a series of circular the beginning and end of'each of which'parts are in ahnement and a series of connecting parts arranged diagonally and connecting the series of circular parts in series to form one continuous groove which hasits alinemen't changed only at long intervals in its length. 7. A record tablet having a laterally unj dulating sound record groove consistingof a.

series of grooved portions of circular a r-; rangement but out of alinement connected in series by a series of diagonally arranged connecting grooves..

'8. A record tablet having a laterally undulating sound record therein consistingof a series of soundrecord portions out of alinement with each other and'connected in series by a series of diagonal record groove '10 series by a series of diagonally arranged c'on portions. necting sound record portions. In testlmony of, WhlCh invention I have 9. A'sound record tablet having a record hereunto set my hand.

groove in which a series of portions thereof are each constructed to have all portions lie E in the same plane across the axis of the tab- Witnesses: let and also at the same distance from the v =R. M. KELLY,

axis and said portions being connected in M. F. Dmsconn. 

